code: def test_empty_error(two_tensor):
      r"""Test that the factorize function raises an error when all factors or their eigenvectors are
      discarded."""
      with pytest.raises(
          ValueError, match="All factors are discarded."
      ):
          qml.qchem.factorize(two_tensor, 1e1, 1e-5)
  
      with pytest.raises(
          ValueError, match="All eigenvectors are discarded."
      ):
          qml.qchem.factorize(two_tensor, 1e-5, 1e1)
  
file_path: pennylane/tests/qchem/test_factorization.py
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: test_empty_error(two_tensor) without return types